The Roadway Departure Crash Countermeasure Tool (RDCCT) was developed by VDOT in conjunction with Kimley-Horn and Associates. This decision tree tool helps users apply a decision matrix to existing roadway departure crash patterns to identify potential low-cost improvements that can be further considered along an identified roadway corridor. The RDCCT provides a decision algorithm that considers both crash and roadway facility data in a user-friendly format, enabling transportation planners and traffic engineers to identify systemic low-cost improvements along high-risk roadways.
Roadway departure related crashes occur when a vehicle departs its travel lane, resulting in a collision with another vehicle, curb, or other roadside features (i.e. trees, utility poles, drainage structures, etc.). There are three categories of potential low-cost countermeasures that the RDCCT considers. The first category includes countermeasures that aim to keep vehicles on the roadway (i.e. rumble strips, wider line markings, etc.). The second category includes countermeasures that aim to provide for a safe recovery back onto the roadway (i.e. pavement wedge, shoulder widening, etc.). The third category of countermeasures aims to reduce the potential severity of collisions occurring on the roadside (i.e. tree removal, barriers, etc.).
Together, these three categories provide a comprehensive and strategic approach to addressing roadway departure related crash patterns. Although several potential countermeasures are available for consideration, the applicability and feasibility for each is dependent on existing roadway geometry, pavement condition, roadway type (i.e. tangent or horizontal curve) and crash patterns. The RDCCT was developed to consider these constraints, such that only countermeasures that are applicable to the corridor are being identified for further consideration.
UVA TTA/VA LTAP contracted with Kimley-Horn to conduct two training sessions with City of Charlottesville and City of Richmond engineering staff to test-drive the RDCCT with existing roadways having roadway departure related crash patterns. Travis Bridewell, Operations Manager for the City of Richmond, and Brennen Duncan, City Traffic Engineer for the City of Charlottesville, participated in one-on-one sessions with Ben Reim, a transportation engineer with Kimley-Horn. At each session, they reviewed the tool and its available resources, analyzed actual crash data for their specific locale, and interpreted preliminary results from the RDCCT.
The Charlottesville session focused on a segment of Barracks Road where crash data revealed a significant number of roadway departures, some of which included overturned vehicles. Several potential countermeasures were identified for further consideration from the RDCCT, including pavement marking improvements and horizontal curve signing.
The Richmond session focused on two sections of Cherokee Road, located between Huguenot Road and Forest Hill Avenue. Crash data revealed several crashes which involved vehicles leaving the roadway and striking roadside objects. The RDCCT identified several potential countermeasures for further consideration, including pavement wedge application, tree removal, and the installation of object markers.
Importantly, Bridewell and Duncan provided input to guide future implementation of the tool in other localities. “Travis and Brennen were invaluable in providing key insights from the transportation professional’s point of view,” explained Reim. “They helped shape possible iterations of the tool as it relates to the RDCCT being incorporated into potential safety funding applications, as well as potential adaptations that could assist in addressing roadway departure related crashes at intersections.”
For additional information, contact Ben Reim at email@example.com.